feat: productionize local service — fix signal pipeline, lower thresholds, add company-name ticker extraction

- Point Ollama to local instance via host.docker.internal, use gemma3 model
- Remove Docker Ollama service (using host's Ollama instead)
- Add company-name-to-ticker mapping (Apple→AAPL, Tesla→TSLA, etc.) for RSS articles
- Lower signal thresholds for faster feedback with paper trading:
  - FinBERT confidence: 0.6→0.4, signal strength: 0.3→0.15
  - News strategy: article_count 2→1, confidence 0.5→0.3, score ±0.3→±0.15
- Fix market data BarSet access bug (BarSet.__contains__ returns False incorrectly)
- Fix market data SIP feed error by switching to IEX feed for free Alpaca accounts
- Fix nginx proxy routing for /api/auth/* to api-gateway /auth/*
- Add seed_sample_data script
- Update tests for new thresholds and alpaca mock modules

services/market_data/main.py

@@ -72,6 +72,7 @@ async def _fetch_historical_bars(
 
     Returns the total number of bars published.
     """
+    from alpaca.data.enums import DataFeed
     from alpaca.data.requests import StockBarsRequest
 
     total_published = 0
@@ -86,10 +87,14 @@ async def _fetch_historical_bars(
                 timeframe=timeframe,
                 start=start,
                 limit=limit,
+                feed=DataFeed.IEX,
             )
             bars = await asyncio.to_thread(client.get_stock_bars, request)
 
-            ticker_bars = bars[ticker] if ticker in bars else []
+            try:
+                ticker_bars = bars[ticker]
+            except (KeyError, IndexError):
+                ticker_bars = []
             for bar in ticker_bars:
                 msg = _bar_to_dict(ticker, bar)
                 await publisher.publish(msg)
@@ -120,6 +125,7 @@ async def _poll_latest_bars(
 
     Returns the number of bars published.
     """
+    from alpaca.data.enums import DataFeed
     from alpaca.data.requests import StockBarsRequest
 
     published = 0
@@ -134,10 +140,14 @@ async def _poll_latest_bars(
                 timeframe=timeframe,
                 start=start,
                 limit=1,
+                feed=DataFeed.IEX,
             )
             bars = await asyncio.to_thread(client.get_stock_bars, request)
 
-            ticker_bars = bars[ticker] if ticker in bars else []
+            try:
+                ticker_bars = bars[ticker]
+            except (KeyError, IndexError):
+                ticker_bars = []
             if ticker_bars:
                 # Publish only the most recent bar
                 bar = ticker_bars[-1]